package summer_vacation.liqiqi.day45;

/**
 * Created by uw on 2015/9/2.
 */
public class jiecheng {
    public static void main(String[] args){
        int ji=1;
        int sum=0;
        for(int a=1;a<=20;a++) {
            ji = ji * a;
            sum = sum + ji;
            a++;
        }
        System.out.println("1!+2!+3!+....20!="+sum);
    }
}
